Fibroin spinning solutions



UNITED STATES PATENT OFFICE rmaom srnmme SOLUTIONS Rudolph S. Bley, Mllligan College, Tenn., assignor to North American Rayon Corporation, New York, N. Y., acorporation of Delaware No Drawing.

OriginalNo. 2,145,856, dated Februan i, 1939, Serial No. 203,443, April 21, 1938, which is a division of application Serial No. 59,912, January 20, 1936. Application for reissue March 16, 1939, Serial No. 262,235

16 Claims.

The present invention relates to a process of manufacturing solutions of proteins, such as 11-- broln casein, gelatin, wool and alginic acid, from which the proteins may be precipitated by suitable reagents.

One object of this invention is to prepare a spinning solution containing a protein selected from the group consisting of silk fibroin, wool, gelatin, alginic acid and casein from which artiflcial products, such as filaments, yarns, ribbons, films, etc., may be formed.

Another object of my invention has to do with the preparation of a spinning solution bydissolving fibroin in a quaternary benzyl substituted ammonium base.

A third object of my invention relates to the manufacture of fibroin spinning solutions by dissolving a fibroin, such as natural silk, in a quaternary benzyl substituted ammonium hydroxide.

A fourth object of this invention has to do with the preparation of a spinning solutioncontaining cellulose or cellulose derivatives and iibroin from which these substances may be precipitated in hydrated form.

Other objects of my invention will become apparent to those skilled in the art 'from a study of the following specification.

I am well aware that processes are already known for dissolving silk fibroin in ammoniacal copper hydroxide, etc., to produce spinning solutions therefrom.' However, such solutions have proven unstable due to degradation of the fibroin molecule, this degradation resulting in a decrease in viscosity of such fibroin solutions. In accordance with the present invention this degradation of the fibroin molecule is substantially counteracted by dissolving natural silk in solutions of quaternary benzyl substituted ammonium bases. I have found 'by experimentation that fibroin may be rapidly and completely dissolved in highmolecular organic ammonium bases having the general structure canon. R.

in which R1, R2 and R: represent alkyl, aryl ll ide is an excellent solvent for fibroin, wool, etc.,

other quaternary benzyl-ammonium hydroxides may be used for this purpose, such as triethylbenzyl-ammonium hydroxide, dimethyl-phenylbenzyl-ammonium hydroxide, diethyl phenyl benzyl ammonium hydroxide, dibutyl phenyl I benzyl ammonium hydroxide, dimethyl toiylbenzyl ammonium hydroxide, dimethyl tolylbenzyl ammonium hydroxide, dimethyl amyl benzyl-ammonium hydroxide, dimethyl-dibenzylammonium hydroxide, benzyl-'pyridonium hydroxide, dlbutyl-dibenzyl-ammonium hydroxide, tolyl-pyridonium hydroxide, etc. In other words,

- I may use any water-soluble, high-molecular quaternary ammonium hydroxide which has a strong basic reaction and which is able to dissolve fibroin, wool, cellulose, etc. Benzyl substituted ammonium hydroxides are able to dissolve such substances in relatively short periods of time to form clear, filtrable solutions. The fibroin can be precipitated from such solutions by diluting them 90 with water or by causing the ammonium base to react with acids, acid salts and the like. However, it is to be noted that aqueous solutions of benzyl substituted ammonium hydroxides should be preferably of about to strength, i. e., a about 2 normal. It is also preferable to dissolve fibroin in quaternary ammonium bases at an elevated temperature for the formation of clear filtrable solutions. However, care must be exercised to avoid decomposition by the solvent by raising the temperature too high. Although it has been found that such fibroin solutions keep well on standing at ordinary room temperature, the degradation of fibroin may be practically overcome by storing said solutions at a low tem-' perature. The solutions may be diluted to some extent with water without causing precipitation of fibroin provided suitable emulsifying agents, such as trimethyl-benzyl-ammonium oleate, alkali metal salts of fatty acids, etc., are added thereto in suitable proportions.

Any known type of delustering agent which is stable inquatemary ammonium bases, such as oils, pigments, dyestufis, etc., may be dispersed i by suitable means in these fibroin solutions for the production of soft-lustre or colored products therefrom. g

Insteadof using a fibroin-solution per se for theproduction of filaments, yarns, films, etc., I may form mixed spinningsolutions containing 50 for example fibroin and cellulose, since both substances maybedlssolved in quaternary ammonium hydroxides. For this purpose, I may dissolve for example natural silk and cellulose or a cellulose derivative, such as cellulose esters and ethers in a concentrated, aqueous solution of a. benzyl substituted ammonium hydroxide such as trimethylbenzyl ammonium hydroxide, etc. The fibroincellulose 01 fibroln-cellulose derivative solution may be subsequently spun into water, dilute acids or salt solutions to form filaments, yarns, ribbons or films. Solutions may also be spun containing flbroin, cellulose and a rubber latex. The solutions, set forth above, may be spun in funnels like cuprammonlum cellulose or they may be precipitated and coagulated like viscose in setting baths. The coagulated products may be collected on spools or in centrifugal pots. Cellulose sponges may be formed inmolds in well-known manner. Any known delustering agent which is stable in quaternary benzyl substituted ammonium bases may be added in suitable amounts to flbroin, fibroin-cellulose, fibroin-cellulose derivative or fibroin-wool or mixtures thereof to modify the lustre and other physical characteristics of the finished products. The ammonium bases may be recovered from the setting bathsby suitable means and re-employed for the dissolution of fibroin, cellulose, wool, etc., to render the process more economical.

Example I Natural silk, 1. e., fibroin, is dissolved at a moderate temperature in a 25 to solution of trimethyl-benzyl ammonium hydroxide until a solution of sufficient viscosity is obtained. The spinning solution, thus prepared, is spun with the assistance of spinnerettes into an acid setting bath containing for example dilute sulphuric acid andsodlum sulphate. The threads are collected on spools or in pots, washed and dried. Wool, gelatin, alginic acid or casein may be dissolved in similar manner to form solutions which are spun like silk fibroin.

Example If Natural silk and cellulose are dissolved together in a quaternary ammonium hydroxide, preferably trimethyl-benzyl ammonium hydroxide, and

spun as set forth in Example 1. Instead of cellulose or regenerated cellulose, a celluose derivative, l. e., esters and ethersjmay be dissolved together with fibroin. Instead of forming silk fibroin solutions, I may dissolve wool, gelatin, alglnic acid or casein in a quaternary ammonium base, preferably a benzyl substituted ammonium hydroxide, toform spinning solutions which may contain in addition cellulose, regenerated cellulose or cellulose derivatives.

Example III Fibroin, wool, gelatin, alginic acid or casein solutions with or without cellulose additions are diluted with water after the addition of a suitable emulsifying agent, such as trimethyl-benzyl oleate to such extent that the solid phase is not precipitated, spun and after-treated in accordanee with the methods set forth above.

Instead of feeding the spinning solutions, set forth above, singly to the spinning nozzles, I may extrude for example a fibroin solution together with a cellulose solution from a single or a plurality of spinnerettes and obtain composite products consisting of natural silk and cellulose filaments. etc. In this manner, I may also produce mixed products consisting-of natural silk, wool and cellulose, etc. Furthermore, I may admix pigments or other solid and liquid delustrants with my spinning solutions for the production of 75 yarns composed of diiferently'colored filaments.

etc. In other words, according to the present invention, any method known in the rayon art may be used to modify the physical properties of products manufactured from my novel spinning solutions. Instead of completely dissolving the carbohydrates in benzyl substituted quaternary ammonium hydroxide, they may be pretreated therewith and subsequently xanthated with carbon bisulphide to form solutions from which artificial silk may be spun. I wish to emphasize that the substances, set forth'above, may be truly in which R1 and R2 represent a radical selected from the group consisting of alkyl radicals, aryl radicals, aralwl radicals, substituted alkyl radicals, substituted aryl radicals and substituted aralkyl radicals, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures.

2. A spinning solution for the manufacture of artificial products comprising a silk fibroi'n finely dispersed in a quaternary phenyl substituted ammonium base having the structure in which R1 and R: represent a radical selected from the group consisting of alkyl radicals, aryl radicals, aralkyl radicals, substituted alkyl rad icals, substituted aryl radicals .and substituted aralkyl radicals, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures.

3. A spinning solution for the manufacture of artificial products comprising a casein finely dispersed in a quaternary phenyl substituted ammonium base having the structure in which R1 and R: represent a radical selected from the group consisting of alkyl radicals, aryl radicals, arallwl radicals, substituted alkyl radicals, substituted aryl radicals and substituted aralkyl radicals, said solution having the property'of substantially retaining its viscosity on standing for relatively longperiods of time at a temperature not exceeding ordinary room temperatures. a

4. A spinning solution for the manufactureoi artificial products comprising an alginic acid finelydispersed in a quaternary phenyl substituted ammonium base having the structure in which R1 and R2 represent a radical selected from the group consisting of alkyl radicals, aryl radicals, aralkyl radicals, substituted alkyl radicals, substituted aryl radicals and substituted aralkyl radicals, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures. I

5. A spinning solution for the manufacture of artificial products comprising a protein selected from the group consisting of silk fibroin, wool. gelatin, alginic acid and casein finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of. time at a temperature not exceeding ordinary room temperatures.

6. A spinning solution for the manufacture of artificial products comprising a silk fibroin finely dispersed in a dibutyl-pheny1-benzyl-ammonium hydroxide, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures.

7. A spinning solution for the manufacture of artificial products comprising a casein finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures.

8. A spinning solution for the manufacture of artificial products comprising an alginic acid finely dispersed in a dibutyl-phenyl-benzylammonium hydroxide, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding ordinary room temperatures.

9. A spinning solution for the manufacture of artificial products comprising a protein selected from the group consisting of silk fibroin, wool, gelatin, alginic acid and casein finely dispersed in a quaternary phenyl substituted ammonium base having the structure CnH 11 011500 I R0 R3 in which R1 and R0 represent a radical selected from the group consisting of alkyl radicals, aryl radicals, aralkyl radicals, substituted alkyl radicals, substituted aryl radicals and substituted aralkyl radicals, said solution having the properin which R1 audit: represent aradical selected from the group consisting of alkyl radicals, aryl artificial products comprising a casein finely dispersed in a quaternary phenyl substituted ammonium base having the structure finely dispersed in .a quaternary phenyl substituted ammonium base having the structure in which R1 and R: represent a radical selected from the group consisting of alkyl radicals, aryl radicals, aralkyl radicals, substituted alkyl radi-' cals, substituted aryl radicals and substituted aralkyl radicals together with a cellulosic substance selected from the group consisting of cellulose, cellulose esters and cellulose ethers, said solution having the property of substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding normal room temperatures.

13; A spinning solution for the manufacture of artificial products comprising a protein selected from the group consisting of silk fibroin, wool, gelatin, alginic acid and casein finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide together with a cellulosic substance selected from the group consisting of cellulose, cellulose esters and cellulose ethers, said solution having the property of substantially retaining its viscosity on standing for relatively-long periods of time at a temperature not exceeding ordinary room temperatures.

14. A spinningsolution for the manufacture of artificial products comprising a silk fibroin finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide together with a cellulosic substance selected from the group consisting of cellulose, cellulose esters and cellulose ethers, said solution having the property of substantially retaining its viscosity on standing for relatively long perl-' ods of. time at a temperature not exceeding ordinary room temperatures. 7

15. A spinning solution for the manufacture of artificial products comprising 'a casein finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide together with a cellulosic substance selected from the group consisting of cellulose.

cellulose esters and cellulou ethers, said solution having the property 01 substantially retaining its viscosity on standing torrelatively long periods of time at a temperature not exceeding ordinary room temperatures.

16. A spinning solution for the manufacture of artificial products comprising an alginic acid finely dispersed in a dibutyl-phenyl-benzyl-ammonium hydroxide together with a cellulosic substance selected from the group consisting of cellulose, cellulose esters and cellulose ethers,

.said solution having the property 01 substantially retaining its viscosity on standing for relatively long periods of time at a temperature not exceeding' ordinary room temperatures.

RUDOLPH S. BLEY. 

